A suspension arm arranged in such a scanning device is usually designed in the form of a two-arm lever and is, in its center of gravity between the two lever arms, provided with a bearing that is arranged on a support in order to allow the suspension arm to make a movement about at least one axis. A pickup, for example an optical head having a focal lens and intended for emission of a light beam, in particular a laser beam, onto an optical disk (disk-shaped data carrier) designed as an information carrier and for reception of the beam reflected by said optical disk is arranged at one end of said suspension arm. Therein, the disk is supported by a supporting device and is caused to make a rotational motion. The end of the suspension arm, which is provided with the optical head, is movable in the form of an arc in a plane extending in parallel to the recording surface of the optical disk for tracking and perpendicularly to this plane for focusing. To achieve this, the suspension arm is provided with magnetic drives, wherein at least that one of said magnetic drives that is intended for the tracking motion is allocated to the other end of the suspension arm. Such a suspension arm allows to achieve short times of access to various locations on the recording carrier.
Such suspension arm actuators are, for example, described in EP-A-0 400 570, in JP-A-5128580, in JP-A-2004227760, in US 2004/0148619 A1, and in KR 1020040108029 A.
The suspension arm actuator described in US 2004/0148619 is arranged on a support such that it can be pivoted about an axis and, to achieve said pivoting, comprises a magnetic drive at that end region that is arranged opposite to the optical head having a focal lens, said magnetic drive being formed of a magnetic arrangement permanently arranged on the support and of a coil arranged on the suspension arm, with control of the operating current of said coil. On the pivot axis side facing away from the magnetic drive, that is on the side of the focal lens, the suspension arm comprises an elastic region, which supports the optical head at its free end. A second magnetic drive formed with the suspension arm is allocated to said elastic region on the head side thereof, said elastic region being partially enclosed by the remaining suspension arm and said second magnetic drive being able to move said free end and, thus, the head in focusing direction.